if there is a clearance, the ball joint (21) lifts under the action of the spring (25); this results in a vacuum in the lower chamber (27), which opens the valve (23)

the pressure between the two chambers (27) and (28) is equal; the valve (23) closes under the action of the spring (24), the two chambers are isolated

Compression phase (valve lift) (J)
:

as soon as the cam presses on the cam follower, the pressure increases in the lower chamber (27), the valve (23) is pressed against its seat; the hydraulic tappet is in stop function mode, the movement is transmitted in its entirety to the valve

Engine oil pressure at 80°C measured in place of the pressure switch
.

engine code

RHZ

RHY

check 1minimum pressure (bar(s))

1000 rpm2

1000 rpm2

check 2minimum pressure (bar(s))

2000 rpm2.8

2000 rpm2.8

check 3minimum pressure (bar(s))

3000 rpm3.8

3000 rpm3.8

check 4minimum pressure (bar(s))

4000 rpm4

4000 rpm4

8 - 4 -
ENGINE OIL CHANGE

The engine oil must be changed with the engine hot just after switching off the engine
.

The engine can be drained by suction (End piece ø 14 mm)
.

It is still possible to drain the engine by removing the drain plug from the sump
.

9 -
AIR SUPPLY CIRCUIT

9 - 1 -
THE INDUCTION CIRCUIT

(40) Exhaust manifold (Cast iron)
.

(41) Inlet manifold (Aluminium alloy)
.

(42) EGR valve
.

(43) EGR valve/manifold connection pipe
.

(44) The air inlet hose (Aluminium alloy)
.

(45) Vacuum pump
.

The Exhaust Gas Recirculation pipe is secured by
:

1 clic clip(s) on the EGR valve (42)

2 bolt(s) on the air inlet union (44)

The EGR valve (42) is secured by 2 bolts on the exhaust manifold (40)
.

9 - 2 -
EXHAUST GAS RECIRCULATION

The role of the EGR system is to reduce the amount of nitrous oxide (NOx) expelled in the exhaust gases
.

The nitrous oxides are produced by the combination of the nitrogen and the oxygen in the intake air under the effect of a very high temperature (greater than 1800 degrees C)
.

During certain phases of operation the EGR reduces the amount of oxygen available in the cylinder
.

The EGR valve (42) is subjected to a vacuum from the vacuum pump (45) secured at the end of the camshaft and this authorises recirculation of the exhaust gases to the air union (44)
.

The recirculation is of the progressive type managed by mapping
.

The opening of the EGR valve (42) is controlled by the EGR solenoid valve which is managed by the engine management control unit which receives the following data
:

coolant temperature

engine speed

engine load (the position of the accelerator pedal)

9 - 3 -
TURBOCHARGER PRESSURE REGULATION SOLENOID VALVE

(42) EGR valve
.

(45) Vacuum pump
.

(46) Turbocharger pressure regulation solenoid valve
.

(47) EGR solenoid valve
.

(48) Turbocharger
.

(49) Turbo regulation valve
.

Controlled by the ECU, this solenoid valve enables it to regulate the intake pressure via the turbo regulation valve (49)
.

10 -
PRE-POST HEATING

(1150) Pre-heat control unit
.

(1160) Glow plugs
.

(1320) Engine management control unit
.

(V1150) Pre-heat warning lamp
.

10 - 1 -
PRE-HEATING

As soon as ignition is switched on : The engine management control unit supplies the glow plugs and controls the lighting of the warning light on the instrument panel, depending on the coolant temperature; The pre-heating time varies depending on the coolant temperature
.

NOTE :
the warning light on the instrument panel only comes on during the pre-heating phase; it comes on for the duration of the pre-heating
.

coolant temperature

pre-heating time(second(s))

-30°C

20

-10°C

5

0°C

0.5

+18°C

0

If the starter is not operated, when the warning light goes out, the glow plugs remain supplied for a maximum of 10 seconds
.

During the starting phase, the glow plugs are supplied under the following conditions
:

the coolant temperature is below 20 degrees C

the engine runs at more than 70 rpm for 0.2 second(s)

10 - 2 -
POST HEATING

Post-heating consists of prolonging the operation of the glow plugs for a maximum of 60 seconds from the end of the starting phase
.

Parameters which could interrupt post-heating
:

coolant temperature greater than 20 degrees C

flow injected greater than 35 mm3

engine speed above 2000 rpm

11 -
FUEL SYSTEM

11 - 1 -
PRESENTATION

This engine is fitted with a new COMMON RAIL direct injection system from BOSCH
.